JPH11181020A - Production of epoxidized block copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an epoxidized block copolymer in small residual organic solvent amount without almost causing heat deterioration. SOLUTION: In recovering an epoxidized block copolymer from an epoxidation reaction solution, the reaction solution is fed to a stirring membrane type evaporator, preferably having a structure capable of forcibly discharging the concentrate to discharge port of the concentrate and an organic solvent is evaporated to concentrate epoxidation reaction solution and then, the organic solvent is removed from the concentrate by a bent-type twin screw extruder 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an epoxidized block copolymer having a low residual organic solvent content by effectively desolvating an epoxidation reaction solution in two stages. The epoxidized block copolymer according to the production method of the present invention can be used as a molded product itself, or a rubbery polymer or a resinous polymer modifier or modification aid, an adhesive, a sealant, Suitable for asphalt modifiers and the like.

[0002]

2. Description of the Related Art A block copolymer comprising a vinyl aromatic hydrocarbon compound and a conjugated diene compound is transparent and has the same elasticity at room temperature as vulcanized natural rubber or synthetic rubber without vulcanization. Further, since it has the same processability as a thermoplastic resin at a high temperature, it is widely used in the fields of various modifiers and adhesion. For the purpose of further improving the above performance, an epoxidized block copolymer in which a carbon-carbon double bond derived from a diene block of a block copolymer has been epoxidized has already been proposed. Such an epoxidized block copolymer is produced by first performing an epoxidation reaction in an organic solvent and then recovering the epoxidized block copolymer uniformly dissolved in the solvent or present in a slurry form from the reaction solution. Is done.

[0003] As a method for recovering an epoxidized block copolymer from a reaction solution, a steam stripping method is well known. This is a method in which an organic solvent solution or slurry containing an epoxidized block copolymer, which is a reaction solution, is poured into hot water, the organic solvent is distilled together with steam, and the epoxidized block copolymer is precipitated in a crumb form. Yes, for example, JP-B-55-7457, JP-B-55-7457
No. 22489, Japanese Patent Publication No. 58-10411, and the like. The obtained crumb-like epoxidized block copolymer generally removes water in a dehydration / drying step. JP-A-59-53504 discloses a method in which a metal oxide or a metal carbonate is added to a crumb obtained by a steam stripping method, followed by drying with a dryer. Japanese Patent Application Laid-Open No. 61-218614 discloses a method in which a crumb-like substance obtained by a steam stripping method is reduced in water content by a dehydrator, and then water is further removed by a twin-screw vented extruder. .

[0004]

However, the steam stripping method requires many steps such as a step of depositing crumb, a step of solid-liquid separation, and a step of dehydration and drying, so that the operation is not easy. In particular, if an appropriate surfactant is not selected at the time of steam stripping, a large amount of deposited crumbs may adhere to the inner wall of the steam stripping tank, the stirring blade, or the like, and the operation may become impossible. Also,
When the precipitated crumb is dehydrated with a dehydrator, it may be difficult to bite into the screw of the dehydrator depending on the shape of the crumb and the like. Furthermore, a large amount of steam is required for removing the solvent, which is economically problematic.

On the other hand, to solve these problems of the steam stripping method, the solvent is directly removed from the organic solution containing the epoxidized block copolymer by using an evaporator to remove the epoxidized block copolymer. There is a method for recovering the wastewater, which is disclosed in JP-A-2-187404, JP-B-5-387.
No. 62, and Japanese Patent Publication No. 7-681. However, the direct desolvation treatment from the epoxidation reaction solution is superior to the steam stripping method in that it is economical and requires fewer treatment steps, but the finally obtained epoxidized block copolymer is thermally decomposed. May be inferior in stability. In addition, gel is particularly likely to be generated during the treatment step, and the hue of the epoxidized block copolymer may decrease.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors studied a method for producing an epoxidized block copolymer, and as a result, concentrated the epoxidized reaction solution with a stirred film evaporator. Then, it was found that the above-mentioned problems could be solved by so-called two-stage desolvation in which the solvent was removed by a twin-screw vented extruder, and the present invention was completed.

That is, the present invention provides a block copolymer (C) comprising a polymer block (A) mainly composed of a vinyl aromatic hydrocarbon compound and a polymer block (B) mainly composed of a conjugated diene compound, or a block copolymer thereof. The epoxidized block copolymer (E) obtained by epoxidizing the hydrogenated product (D) in an organic solvent having a copolymer concentration of 5 to 50% by weight is recovered from the epoxidation reaction solution. An epoxidized block copolymer is supplied to a stirred film type evaporator to evaporate the organic solvent, concentrate the epoxidation reaction solution, and then remove the organic solvent from the concentrated solution by a twin-screw vented extruder. It is intended to provide a manufacturing method. The present invention also provides a method for producing the epoxidized block copolymer, wherein the epoxy equivalent of the epoxidized block copolymer (E) is 140 to 15,000 or 200 to 12,000. The operating conditions of the stirring film type evaporator are as follows: temperature: 80 to 300 ° C., internal pressure: 760 mm
Hg or less; and a method for producing the epoxidized block copolymer. The present invention also provides a method for producing the epoxidized block copolymer, wherein the stirring film type evaporator has a structure capable of forcibly discharging the concentrated liquid to a concentrated liquid discharge port. Furthermore, the operating conditions of the twin-screw vented extruder are as follows:
To 300 ° C. and an internal pressure of 500 mmHg or less. In addition, the present invention provides a method for producing the epoxidized block copolymer, wherein the content of the residual organic solvent in the produced epoxidized block copolymer is 1,000 ppm or less. Hereinafter, the present invention will be described in detail.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The block copolymer (C) referred to in the present invention includes a polymer block (A) mainly composed of a vinyl aromatic hydrocarbon compound and a polymer block (C) mainly composed of a conjugated diene compound. And B).
Further, the hydrogenated product (D) of the block copolymer refers to the hydrogenation of a carbon-carbon double bond present in the copolymer block (B) of the block copolymer (C) by a partial hydrogenation reaction. Means what you do. Furthermore, the epoxidized block copolymer (E) referred to in the present invention refers to a carbon-carbon double bond present in the copolymer block (B) in the block copolymer (C) or its hydrogenated product (D). Epoxidized copolymer.

Examples of the vinyl aromatic hydrocarbon compound that can constitute the block copolymer (C) include various alkyl-substituted styrenes such as styrene and α-methylstyrene, alkoxy-substituted styrene, vinylnaphthalene, alkyl-substituted vinylnaphthalene, divinyl Benzene, vinyltoluene and the like can be mentioned. Of these, styrene is preferred. These can be used alone or in combination of two or more.

Examples of the conjugated diene compound which can constitute the block copolymer (C) include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-1,3.
-Butadiene, 3-butyl-1,3-octadiene, phenyl-1,3-butadiene and the like. Among these, 1,3-butadiene and isoprene are inexpensive,
It is preferable because it is easily available. These can be used alone or in combination of two or more.

The copolymer composition ratio (vinyl aromatic hydrocarbon compound / conjugated diene compound (weight ratio)) of the vinyl aromatic hydrocarbon compound and the conjugated diene compound which can constitute the block copolymer (C) is preferably It is 5/95 to 80/20, more preferably 10/90 to 70/30. Further, the block copolymer (C) which can be used in the present invention
Preferably has a number average molecular weight of 5,000 to 500,0.
00, more preferably 10,000-100,
000. When the molecular weight is lower than 5,000, the properties of the rubber-like elastic body are hardly exhibited, and when the molecular weight is high, it is difficult to melt, which is not preferable. Here, the number average molecular weight means a standard polystyrene equivalent molecular weight measured by a GPC method.

The structure of the block copolymer (C) is not particularly limited. For example, ABA, BAB
A block copolymer of a vinyl aromatic hydrocarbon compound represented by -A, ABABA, or the like and a conjugated diene compound may be used. The structure of the molecule itself may be any of linear, branched, and radial structures, and may be an arbitrary combination thereof. In the block copolymer, the vinyl aromatic hydrocarbon compound may be distributed uniformly or in a tapered shape. In addition, the copolymerized portion may include a plurality of portions where the vinyl aromatic hydrocarbon compound is uniformly distributed and / or a plurality of portions where the vinyl aromatic hydrocarbon compound is distributed in a tapered shape.

The method for producing the hydrogenated product (D) of the block copolymer is not particularly limited, and any method may be used. For example, Japanese Patent Publication No. 42-8704
And JP-B-43-6636, for example, a method of hydrogenating the block copolymer (C) in an inert solvent in the presence of a hydrogenation catalyst. Although the amount of hydrogenation is not particularly limited, it is necessary that unsaturated carbon bonds capable of reacting with the epoxidizing agent remain in the molecule of the hydrogenated product (D) when the epoxidation reaction is subsequently performed.

Epoxidation is carried out by dissolving the block copolymer (C) or its hydrogenated product (D) in a suitable organic solvent and then using an epoxidizing agent. The concentration of the copolymer in the organic solvent is preferably 5 to 50% by weight, and the site to be epoxidized by the epoxidizing agent is a carbon-carbon double bond present in the copolymer block (B). is there. The dissolution of the block copolymer (C) in the organic solvent includes the case where the copolymer (C) exists in a slurry state.

Examples of the organic solvent which can be used in the epoxidation include linear and branched hydrocarbons such as pentane, hexane, heptane and octane, and alkyl-substituted derivatives thereof, and cyclopentane, cyclohexane and cycloheptane. Alicyclic hydrocarbons and their alkyl-substituted derivatives, benzene, naphthalene, toluene, aromatic and alkyl-substituted aromatic hydrocarbons such as xylene, methyl acetate,
Examples include aliphatic carboxylic acid esters such as ethyl acetate and propyl acetate, and halogenated hydrocarbons such as chloroform. Among these, cyclohexane, ethyl acetate, chloroform, toluene, xylene and hexane are used because of the solubility of the block copolymer (C) or its hydrogenated product (D) and the ease of recovery of the organic solvent and other factors. Is preferred.

Epoxidizing agents that can be used in the epoxidation reaction include organic peracids such as peracetic acid, perbenzoic acid, formic acid, trifluoroperacetic acid, hydrogen peroxide, hydrogen peroxide and low molecular weight compounds. And the like in combination with the above fatty acid. Of these, peracetic acid, which is industrially produced in large quantities, is inexpensive because it is produced in a large amount, and has relatively high stability is preferable as the epoxidizing agent. At the time of epoxidation, a catalyst can be used if necessary.

The amount of the epoxidizing agent used is not particularly limited, and the reactivity of the epoxidizing agent used, the desired degree of epoxidation, the block copolymer (C) used or its hydrogenated product Any appropriate amount can be used depending on conditions such as the number of carbon-carbon double bonds in (D). The epoxy equivalent of the finally obtained polymer (E) is 140 to 1
It is 5,000, more preferably 200 to 12,000. If the epoxy equivalent is smaller than 140, the elastic properties of the polymer are hardly exhibited, which is not preferable.
If it is larger than 000, specific physical properties due to epoxidation are hardly developed, which is not preferable. The epoxy equivalent is calculated as epoxy equivalent = 1,600 / {oxirane oxygen concentration in epoxidized block copolymer (wt%)}, and represents the weight of epoxidized block copolymer per mole of oxirane oxygen. . The oxirane oxygen concentration is determined by titration using an acetic acid solution of hydrogen bromide. When the epoxy equivalent is large, the oxirane oxygen concentration decreases, and when it is small, the oxirane oxygen concentration increases. The epoxy equivalent can be arbitrarily selected by adjusting the amount of the epoxidizing agent.

The epoxidation reaction temperature depends on the epoxidizing agent used, the organic solvent used, the type and amount of the block copolymer (C) or its hydrogenated product (D), and is not particularly limited. For example, when peracetic acid is used as the epoxidizing agent, the reaction temperature is preferably from 0 to 7
0 ° C. If the temperature is lower than 0 ° C., the reaction rate is low. If the temperature is higher than 70 ° C., the formed epoxy group is opened, and the decomposition of peracetic acid proceeds, which is not preferable. In order to improve the stability of peracetic acid, phosphates may be added to the reaction system during the epoxidation reaction. Epoxidation reaction time is 0.1 ~
It is preferable to select from 72 hours, more preferably from 0.2 to 10 hours, from the viewpoint of productivity. After completion of the epoxidation reaction, it is preferable to neutralize the acids generated during the epoxidation reaction with an aqueous alkali solution or to wash the epoxidation reaction solution with water. Washing may be performed continuously or in a batch system.

According to the present invention, the epoxidation reaction solution of the epoxidized block copolymer thus obtained is subjected to a first-stage concentration by removing an organic solvent by a stirred film evaporator, and then to a second-stage deconcentration. As a solvent, the remaining volatile components are removed by a twin-screw vented extruder. The stirring film type evaporator uses a general device as long as it scrapes the liquid film descending on the heat transfer surface by the rotating scraping plate to promote heat transfer and make the evaporation uniform. Among them, those having a structure capable of forcibly discharging the concentrated liquid to the concentrated liquid outlet are particularly preferable. Since the evaporator having such a structure is capable of sending a high-viscosity substance beyond the gravity gravity falling region, it is possible to reduce the stagnation of the resin in the evaporator and to reduce the quality deterioration such as gel generation. It is.

The operating temperature, internal pressure, and number of rotations of the stirring blade of the stirring film type evaporator are determined in consideration of the processing capacity, the characteristics of the polymer (viscosity, thermal stability, etc.), the type and concentration of the organic solvent, the quality of the product, and the like. Can be selected as appropriate. The preferred temperature in the evaporator is 80 to 300 ° C, more preferably 100 to 250 ° C.
° C. If the temperature of the evaporator is lower than 80 ° C., the organic solvent cannot be sufficiently removed, while if it is higher than 300 ° C., a large amount of gel is generated in the polymer, which is not preferable. The internal pressure of the agitated film type evaporator is preferably 760 mmHg or less, more preferably in the range of 400 to 1 mmHg. In addition,
The internal pressure of the agitated film type evaporator refers to the pressure at the location showing the lowest pressure in the gas phase portion in contact with the resin in the agitated film type evaporator. When the internal pressure is higher than 760 mmHg, the organic solvent is not sufficiently removed, which is not preferable. In addition, the rotation speed of the stirring blade of the stirring film type evaporator is such that the shearing speed is 100 to 5,0.
It is preferable to set so as to be 00 sec ^-1 .

The twin-screw vent type extruder is preferably an extruder having at least one, preferably 1 to 10, and more preferably 1 to 5, vent portions for deaeration. Also, the rear vent can be used or not. As a twin-screw vent type extruder having such a structure, L / D
= 2 to 50, preferably 4 to 45 (L is the length of the screw, D is the outer diameter of the screw), and the meshing structure of the screw is “meshing”, “non-meshing”.
And the rotation direction may be either the same direction or a different direction. In general, a twin-screw self-cleaning evaporator, a continuous kneader, or the like may be used instead of the twin-screw vented extruder, but the residence time of the resin is shorter than that of the twin-screw vented extruder. Epoxidized block copolymer, which is the object of the production method of the present invention, is not preferred because it has problems such as deterioration of quality such as gel formation.

The heating conditions from the barrel side of the twin-screw vent type extruder, the pressure inside the extruder, the number of screw rotations, the processing capacity, the characteristics of the polymer (viscosity, thermal stability, etc.), the type and concentration of the organic solvent And the quality of the product, the balance of the devolatilization capacity of the agitated film type evaporator, etc. can be appropriately selected. The temperature in the extruder is 80 to 300 ° C, more preferably 10 to 300 ° C.
0-250 ° C. Note that a different temperature can be set for each barrel. If the temperature of the extruder is lower than 80 ° C., the organic solvent is not sufficiently removed, while if it is higher than 300 ° C., a large amount of gel is generated in the polymer, which is not preferable. The internal pressure of the extruder is preferably 500 mmHg or less,
More preferably, it is selected from the range of 400 to 1 mmHg. The internal pressure of the extruder usually means a value read by a pressure gauge attached to a vent. If the internal pressure of the extruder is higher than 500 mmHg, the organic solvent is not sufficiently removed, which is not preferable. The screw rotation speed of the extruder is preferably set so that the shear rate is 100 to 2,000 sec ^-1 . Further, by adding a small amount of water from an appropriate position in the extruder, the amount of the residual organic solvent in the product epoxidized block copolymer can be reduced.

In the present invention, the solvent can be removed by shortening the residence time by removing the organic solvent and removing the organic solvent in two steps as described above, and the product can be manufactured without giving a long heat history. can do. The organic solvent concentration in the epoxidized block copolymer solution is adjusted to 5 to 5 with a stirred film evaporator.
Since it can be reduced to 70% by weight, preferably 20 to 40% by weight, a small twin-screw vented extruder can be used for the second-stage evaporator to be subsequently used. The content of the residual organic solvent in the epoxidized block copolymer finally obtained in this way is 5,000 ppm or less, more preferably 2,000 ppm or less, and especially 1,000 p
pm or less. If the content of the residual organic solvent is more than 5,000 ppm, it is not preferable because foaming occurs at the time of forming a molded article and odor may be generated. still,
The adjustment of the residual organic solvent content can be performed by changing conditions such as the temperature of the evaporator to be used, the pressure inside the evaporator, and the processing speed.

In the production method of the present invention, various additives such as a heat stabilizer, an antioxidant, a cross-linking agent, a UV absorber, or an additive may be used in any step until the epoxidized block copolymer is finally obtained. This includes the case where an inorganic filler such as silica, talc or carbon, a softener such as a plasticizer or oil is added.

The epoxidized block copolymer produced in the present invention may be in the form of a strand, a pellet, a foamed crumb,
Any of a granular form and a powder form can be used, but a pellet form is preferred. In addition, the pellets and the like,
It can be molded products such as sheets, films, injection molded products of various shapes, hollow molded products, etc., home appliances, automobile parts,
Materials such as industrial parts, household goods, toys and the like can also be used. Further, it can be used as a modifier for various thermoplastic resins, a material for an adhesive or an adhesive, or an asphalt modifier.

[0026]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. “%” Indicates “% by weight” unless otherwise indicated.

Example 1 300 parts by weight of a polystyrene-polybutadiene-polystyrene block copolymer (SBS, "TR-2000" manufactured by Nippon Synthetic Rubber Co., Ltd.) were completely dissolved in 1,500 parts by weight of ethyl acetate. 169 parts by weight of a 30% solution of peracetic acid in ethyl acetate was continuously added dropwise thereto, and an epoxidation reaction was carried out at 40 ° C. for 3 hours with stirring.
Next, the reaction solution was returned to room temperature and washed with pure water to obtain an ethyl acetate solution of an epoxidized polystyrene-polybutadiene-polystyrene copolymer (ESBS). The concentration of volatile components in the solution of the epoxidized block copolymer is 70% by weight (the concentration of the epoxidized block copolymer is 30% by weight).
Met. The acid value of this solution was 1.0 mgKOH / g. This solution was supplied to a stirred film type evaporator having a heat transfer area of 0.5 m ² having a screw for feeding liquid immediately before the outlet of the concentrated liquid. The stirring film type evaporator has a heating medium supply temperature of 150 ° C., a system pressure of 400 mmHg, and a stirring blade rotation speed of 300 rpm
(Corresponding to a shear rate of 1580 sec ^-1 ). As a result, the concentration of volatiles in the solution of the epoxidized block copolymer was reduced to 25% by weight (the concentration of the epoxidized block copolymer was 75% by weight). Next, the concentrate was supplied to a twin-screw vented extruder without a rear vent having a screw outer diameter of 44 mm, L / D = 42, and four vent portions. The operation of the extruder was performed at a heating medium supply temperature of 150 ° C., a system pressure of 100 mmHg, and a screw rotation speed of 100 rpm (corresponding to a shear rate of 600 sec ⁻¹ ). The production rate of the polymer obtained by the twin-screw vented extruder was 15 kg /
Then, an ethyl acetate solution of the epoxidized block copolymer was supplied to the stirred film type evaporator so as to reach the value of h. FIG. 1 shows the overall flow. Next, the copolymer discharged from the tip of the extruder was pelletized by a cutter. The residual solvent content in the copolymer after the removal of the solvent was 2,300 ppm, and the epoxy equivalent of the copolymer was 520. Also, no foaming of the molded article was observed. The foaming was confirmed by pressing the polymer at 200 ° C. to form a 2 mm thick sheet, and visually observing this sheet. After the operation was completed, the screw of the extruder was pulled out and the inside was visually observed. As a result, no gel was observed and the gel content was 0.1% by weight or less.

(Example 2) In the twin-screw vent type extruder of Example 1, water was added to the extruder from the supply port just before the fourth vent portion.
2 kg / h and the screw rotation speed is 70 rpm
An epoxidized block copolymer was obtained in the same manner as in Example 1 except that the shearing speed was 420 sec ^-1 . The residual solvent content of the obtained polymer was 760 ppm, and the epoxy equivalent of the polymer was 520. Also, no foaming of the molded article was observed. After the operation was completed, the screw of the extruder was pulled out and the inside was visually observed. As a result, no gel was observed and the gel content was 0.1% by weight or less.

Comparative Example 1 An ethyl acetate solution of an epoxidized block copolymer obtained in the same manner as in Example 1 (volatile content: 70% by weight) was provided with a screw for feeding a liquid immediately before the outlet of the concentrated liquid. It was supplied at 66 kg / h to a stirred film type evaporator having a heat transfer area of 0.5 m ² without heat transfer. The stirring film type evaporator has a heating medium supply temperature of 150 ° C., a system pressure of 400 mmHg, and a rotation speed of the stirring blade of 300 rpm (corresponding to a shearing speed of 1,580 sec ⁻¹ ).
I went in. The concentrate stays just before the evaporator outlet,
The concentrate could not be discharged from the evaporator and the operation could not be continued. The gel content was 3.0% by weight.

Comparative Example 2 The twin-screw vented extruder of Example 1 was a horizontal twin-screw self-cleaning evaporator having a screw outer diameter of 100 mm and L / D = 6.
° C, system pressure 100mmHg, screw rotation speed 3
Other than ⁰ rpm (corresponding to a shear rate of 75 sec ^-1 ),
An epoxidized block copolymer was obtained in the same manner as in Example 1. The residual solvent content of the obtained copolymer was 1,1.
It was 50 ppm and the epoxy equivalent of the polymer was 520. Also, foaming of the molded product was not recognized at all,
A large amount of fish eyes were generated, resulting in molding failure.
After the operation was completed, the screw was pulled out, and the inside of the evaporator was opened and visually observed. As a result, adhesion of a resin discolored to yellow on the inner wall of the apparatus and the screw was observed. The gel content is 3.
It was 0% by weight.

[0031]

According to the present invention, an organic solvent is removed from an epoxidation reaction solution by a two-stage desolvation between a stirred film evaporator and a twin-screw vented extruder, thereby providing a long-term heat history. Therefore, the epoxidized block copolymer can be separated from the organic solvent and the epoxidized block copolymer, and the epoxidized block copolymer with little heat deterioration and a small amount of the remaining organic solvent can be produced.

[Brief description of the drawings]

FIG. 1 shows a flow chart of removing an organic solvent from an epoxidation reaction solution of Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reaction tank or intermediate tank 2 Pump 3 Stirred film type evaporator 4, 14 Condenser 5, 15 Recovered solvent tank 6, 16 Recovered solvent 7 Biaxial vent type extruder 8 Condensate 9 First vent port 10 Second vent port 11 Third vent port 12 Fourth vent port 13 Vacuum pump 17 Desolvating resin 18 Water addition port

Claims (7)

[Claims] 1. A block copolymer (C) comprising a polymer block (A) mainly composed of a vinyl aromatic hydrocarbon compound and a polymer block (B) mainly composed of a conjugated diene compound, or a hydrogenated product thereof. (D) is the copolymer concentration of 5 to 5
When the epoxidized block copolymer (E) obtained by epoxidation in an organic solvent of 0% by weight is recovered from the epoxidation reaction solution, the reaction solution is supplied to a stirring film type evaporator to evaporate the organic solvent, A method for producing an epoxidized block copolymer, comprising concentrating an epoxidation reaction solution, and then removing an organic solvent from the concentrate using a twin-screw vented extruder. 2. The process for producing an epoxidized block copolymer according to claim 1, wherein the epoxy equivalent of the epoxidized block copolymer (E) is from 140 to 15,000. 3. The method for producing an epoxidized block copolymer according to claim 1, wherein the epoxy equivalent of the epoxidized block copolymer (E) is from 200 to 12,000. 4. The use condition of the stirring film type evaporator is as follows:
The method for producing an epoxidized block copolymer according to any one of claims 1 to 3, wherein the temperature is from 300 to 300 ° C and the internal pressure is 760 mmHg or less. 5. The epoxidized block according to claim 1, wherein the stirred film type evaporator has a structure capable of forcibly discharging the concentrated liquid to a concentrated liquid discharge port. A method for producing a copolymer. 6. The use condition of the twin screw vent type extruder is a temperature of 8
The method for producing an epoxidized block copolymer according to any one of claims 1 to 5, wherein the temperature is 0 to 300 ° C and the internal pressure is 500 mmHg or less. 7. The epoxidized block copolymer according to claim 1, wherein the content of the residual organic solvent in the epoxidized block copolymer is 1,000 ppm or less. Method.